Electric-cicuit controller.



T. VARNEY.

ELECTRIC CIRCUIT CONTROLLER;

APPLICATION FILED MAY 27. I912.

Patented Feb. 13,1917.

ATTORNEY 2 SHEETS-SHEET I.

T. VARNEY.

ELECTRIC CIRCUIT CONTROLLER, APPLICAHON FILED MAY 2?. 1912.

Patented Feb, 13 1911 2 SHEETS-SHEET 2.

ATTORNEY WITNESSES:

said class.

STATES PATENT ()FFICE.

.FHEODORE VABNEY, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR '10 WESTINGHOUSEELECTRIC AND MANUFACTURING- (JOMPANY, A CDRPORATION OF PENNSYLVANIA.

ELECTRIC'GIRCUIT GON'IRULLER.

Application filed May 27, 1912.

electric circuits and it has special reference to such controllers asare adapted to govern polyphase alternating current motors.

One object of my invention is to provide a controller of the class aboveindicated that shall have a relatively simple and durable means forautomatically returning the controller to its ott' position upon thetailure of volta e in one or more of the liases of the alternatingcurrent source of energy troiii which the controlled motor is supplied.

A. second object of my invention, is to provide a particularly simpleand durable con tact structure for controllers ot' the a tore- Variousnovel features will be hereinafter pointed out.

Figure 1 of the accompanying drawings is an elevation of a controllerconstructed in accordance with my invention, the inclosing tank orcasing being broken away to disclose the operating mechanism and theswitch contacts. v

Figs. 2 and 3 are detail views of the controller operating mechanism,and Fig. -l is a diagrammatic view illustrating the circuit connectionsof a motor control system our bodying the controller of the otherfigures.

Referring to Figs. 1, :2 and 3 of the drawings, the controller hereshown comprises a stationary frame 1 which 'fOl'illS a part of aninclosing casing a cover 62, a lliiiii-containing tank or box 3, whichis removably secured to the frame, a plurality of sets of stationary andmovable contactmembers l, 5, 6 and 7 (liereinaiter referred to as cantacts), an operating mechanism and a release magnet 8.

The stationary contacts 4 and 5 are mounted in parallel rows on aninsulating plate or slab 9, to which they are secured by bolts 10.

The plate or slab 5) is supported in a substaiitially horizontal planeby a pair of yoltes or brackets 'll', which are bolted to Specificationof Letters Patent.

Patented Feb. i3, 1917.

Serial No. 700,055.

lugs 12 of the stationary frame 1 and ex tend down ardly into thefluid-containing tank The brackets 11 are mounted in substantiallyparallel planes and support a shaft 13 which is iiotatively mounted in ahorizontal plane near the center of the tank or box 3.

-A pair of castings 1% are secured to the shaft 13 between, and adjacentto, the re-' spective bearing brackets.

An insulating strip or block 15, which is substantially parallel to theshaft 3, is secured to the castings 1% by bolts 16.

A link 18, which constitutes a portion of the operating mechanism, isconnected to a projection ll of one of the castings let.

A plurality of coiitact-bearing members 19 are mounted on the insulatingblock 15 between the castings 14, and have perforated extensions 20 towhich the contacts 6 and 7 are respectively pivoted.

Each of the contacts ti and 7 is preferably provided with a reniovablecontact tip which cooperates with the corresponding portion of one ofthe stationary contacts 4:

and o.

Each of the movable contacts is further provided with a dmvnwardlyextending bifurcated projection 21, and, a spring 22 is interposedbetween the project-ions of each pair of opposite movable contacts. Eachof the springs 22 is supported by a telescop-.

ing guideQtl having forked ends which engage pins 24; in the bifurcatedprojec tioiis 21.

The contact-bear ng members 19 and the contacts thcii'iselves areprovided with c0- operating stop projections 25, which are tionary rod'28 which is mounted in the frame 1 and is parallel to the shaft 26 andI a centering spring 29, which is coiled about the shaft 26 between apair of pawls 30 and 31.. 1

A pawl engages a notch 3st in a cam 35 which is pivotally supported onthe star- Elli till

tionary frame 1 and prevents the movement of the operating handle 2'? inone direction out of the oil position of the controller.

Abell crank lever 32 is secured to the shaft 26, and the link 18 ispivotally con nected to one of its arms. Its opposite arm constitutes alatching pawl and. is pro vidcd. with notch 37 at its outer end which isadapted to engage one end of a hell crank lever 38. The bell cank lever38 is pivoted. on a stationary pin 39 and its opposite end is connectedto a movable core member so of the release magnet 8.

In addition to the movable core member 2-0, the release magnet comprisesa coil 41 and stationary core; member 452 through which a guide rod d3of the movable member extends.

The movable core member acts vertically and a releasing" pin 4% ismounted directly above it in the cover The pin 44% l as an extension 45that projects through a hole -l6 in the cover 2 and is adapted to engagethe iupper end of the rod 1-3 when pressed downwardly in opposition to aspring ll.

'lhebody of the pin 44 slides in a recess 48 in a boss 49 of the cover2. The spring 47 surrounds the extension 45 and is interposed betweenthe body 4+1 and the bottom of the recess 48.

A pair of relay switches 50 and 51 and coils and 53 of anauto-transhn'mer are siipported within. the frame 1 near the inag net 3.

The tank or box 3 is preferably filled with oil or some other suitableinsulating liquid which tends to quench the elect ic arcs pro duced whenthe cooperating contact 1nemhers are separated.

The circuit coi'lnections for the system and the arrangement of thecontrol contacts are illustrated in Fig. 4. to which reference may nowhe had.

he here shown, the group or l, of stationary contact members comprisescontacts a, Z 0, and (Z, and the group 6 comprises cooperating contactsc, f, g and Z. 'llhe group 5 comprises stationary contacts e', 5 70, Z,we and a, and the group '7 comprises cooperating movable contacts 0, 77,and r.

The controller is adapted to govern the circuits of a three-phaseelectric motor which is supplied with energy from a groin crater 35 orfrom some other suitable source.

The operation of the controller and the circuit connections for thesystem are as follows:

Assuming that the controller occu 'iies its oil position, shown in Fig.l. all all th nioral'ile contacts are separated from cooperatingstationary contacts and the pawl 33 so engages the notch I'll as toprevent n'icvenient of the lever 27 in a clockwise di-- rection. if thelever is moved in a counterthe circuit conductor :37.

clockwise direction, the block 15 and the mo *able contacts are given arotary movement about the shaft 13 as an axis and the movable contacts 7are forced into engage ment with the stationary contacts This is thestarting position of the controller and the operator should. hold thelever in this position until the motor has attained a. material speed.If the lever is released, the contacts will return to the position shownin l l and the pawl 33 will fall back into the notch Ell. if, lunvever,the attendant throws the lever speedily in a clockwise direction irointhe starting position, through the oil position, to the runningposition, the pawl engages the surface oi the cam 85 and passes thenotch 3 3: before the cam an opportunity to resume the posi tion shownin Figll.

i hen the inotor-opcrating,- position is at tained, the end oi? the bellcrank lever 35 engages the notch 37 in the pawl 30 by reason of thecompletion of an electric circuit through the coil ll ol' the releasemagnet R. The controller is accordingly held in the motorcperatingposition as long as the coil 4. 1 continues to lie energized or untilthe pawl is manually rehmsed.

lfn the motor-startingr position oi" thecom troller, the transformercoil is connected across a pair lino conductors it; and 57, the contact.m and n being bridged by the contacts 1''. The transformer coil .73 issimilarly connected across the line conductors 58 and 57, the contactsand y being bridged by the contact 0. tin interniwliate tap 59 of thetransformer coil is conncted. through contacts Z and (j, to one terminal(30 of the motor i l tap 61 of the trans former coil is similarlycminectcd through contacts Z" and p, to a motor terminal. A thirdterminal as of the motor is connected, through contacts r and n, to theline conductor 57.

llclatiyely low-rolta gc energy is accordingly impressed on the motorwindings in the starting position of the controller.

ll icn'lthe controller occupies its motorrunniug position, the motorterminals and as are respectively connected, tl'irouph fjtlw coils ofthe relay switches 51. and 50, to the circuit conductors 5t; and 58, andthe motor terminal 53 is connected directly to As long: as the switches50 and 5 are closed, the coil of the ,u'airiiiet 8 is connected acrossthe circuit con.-

the magnet 8 .ner, ifexcessive current traverses either phase of themotor winding, one of the switches 50 and 51 will open, the coil 8 willbe deenergized and the controller will be permitted to return to its offposition.

\Vhile I have shown my invention as applied to a three-phase motor, itis, of course, not limited in this respect and the circuit connectionsand the contact men' bers may be readily arranged to govern a motor. v

Variations in structural details may also be effected within the spiritand scope of my invention.

I claim as my invention:

1. A controller for electric circuits comprising two sets of stationarycontact terminals, an intermediate rock-shaft, a contact-supportingmember rotatively mounted upon the rock-shaft, two imlependently pivotedsets of contact terminals carried by said supporting member, means forresiliently connecting oppositely disposed pairs of said terminals andmeans for producing such rotative movements of the contact-supportingmember as to effect engagement of the one or the other of its sets ofcontact terminals with the corresponding stationary contact terminals.

2. A controller for electric motors comprising two sets of stationarycontacts, an intermediate rock shaft, a set of movable contactsrotatively supported by the rock shaft, a lever for producing such arotative adjustment of the rock shaft as to bring the movable contactsinto engagement with one set of stationary contacts for motor-startingand into engagement with the other set of two-phase contacts for motorrunning and means dependent upon the engagement of the contacts in themotor-running position for locking the lever to maintain said position.

3. A controller for electric circuits comprising two sets of stationarycontacts, an intermediate rock shaft, a set of movable contact-Waringmembers rotatively supported by the rock shaft, contacts pivotallysecured to the contact-bearing member at opposite sides of the rockshaft, stops for limiting the rotative movement of the movable contactson their pivots, and springs interposed between pairs of movablecontacts and tending to force them against said stops. v

4. A controller for electric circuits comprising two sets of stationarycontacts, an intermediate rock shaft, a set of movable contact-bearingported by the rock shaft, contacts pivotally secured to the movableeontzuzt-bearing mom hers at opposite sides of the rock shaft, stops forlimiting the rotative adjustment of the movable contacts on theirpivots, springs interposed between pairs of opposite movable contactsand tending to force them against said stops, and means for producingsuch rotative movement of the rock shaft as to bring the movablecontacts into en-,

gagement with either the one or the other set of stationary contacts.

In testimony whereof, I have hereunto subscribed my name this ,Zith dayof. May, 1912.

THEODORE VARNEY.

Witnesses:

It. \V. Cornmr n, B. B. Hmns. 4

members rotatively sup-

